| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| |
| #ifndef IMPALA_RUNTIME_SCOPED_BUFFER_H |
| #define IMPALA_RUNTIME_SCOPED_BUFFER_H |
| |
| #include "runtime/mem-tracker.h" |
| |
| namespace impala { |
| |
| /// A scoped memory allocation that is tracked against a MemTracker. |
| /// The allocation is automatically freed when the ScopedBuffer object goes out of scope. |
| /// NOTE: if multiple allocations share the same lifetime, prefer to use MemPool. |
| class ScopedBuffer { |
| public: |
| ScopedBuffer(MemTracker* mem_tracker) : mem_tracker_(mem_tracker), |
| buffer_(NULL), bytes_(0) {} |
| ~ScopedBuffer() { Release(); } |
| |
| /// Try to allocate a buffer of size 'bytes'. Returns false if MemTracker::TryConsume() |
| /// or malloc() fails. |
| /// Should not be called if a buffer is already allocated. |
| bool TryAllocate(int64_t bytes) { |
| DCHECK(buffer_ == NULL); |
| DCHECK_GT(bytes, 0); |
| if (!mem_tracker_->TryConsume(bytes)) return false; |
| buffer_ = reinterpret_cast<uint8_t*>(malloc(bytes)); |
| if (UNLIKELY(buffer_ == NULL)) { |
| mem_tracker_->Release(bytes); |
| return false; |
| } |
| bytes_ = bytes; |
| return true; |
| } |
| |
| void Release() { |
| if (buffer_ == NULL) return; |
| free(buffer_); |
| buffer_ = NULL; |
| mem_tracker_->Release(bytes_); |
| bytes_ = 0; |
| } |
| |
| uint8_t* buffer() const { return buffer_; } |
| |
| int64_t Size() const { return bytes_; } |
| |
| private: |
| MemTracker* mem_tracker_; |
| uint8_t* buffer_; |
| /// The current size of the allocated buffer, if not NULL. |
| int64_t bytes_; |
| }; |
| |
| } |
| |
| #endif |